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[ubsan] Save a ptrtoint when emitting alignment checks

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The alignment check emits a ptrtoint instruction which can be reused in
the call to the diagnostic handler.

llvm-svn: 314749
This commit is contained in:
Vedant Kumar 2017-10-03 01:27:24 +00:00
parent 675cf03f6e
commit 8a7153312b
2 changed files with 11 additions and 7 deletions
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13
clang/lib/CodeGen/CGExpr.cpp
View File

@ -656,6 +656,7 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
} }
uint64_t AlignVal = 0; uint64_t AlignVal = 0;
llvm::Value *PtrAsInt = nullptr;
if (SanOpts.has(SanitizerKind::Alignment) && if (SanOpts.has(SanitizerKind::Alignment) &&
!SkippedChecks.has(SanitizerKind::Alignment)) { !SkippedChecks.has(SanitizerKind::Alignment)) {
@ -666,9 +667,9 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
// The glvalue must be suitably aligned. // The glvalue must be suitably aligned.
if (AlignVal > 1 && if (AlignVal > 1 &&
(!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) { (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
llvm::Value *Align = PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
Builder.CreateAnd(Builder.CreatePtrToInt(Ptr, IntPtrTy), llvm::Value *Align = Builder.CreateAnd(
llvm::ConstantInt::get(IntPtrTy, AlignVal - 1)); PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
llvm::Value *Aligned = llvm::Value *Aligned =
Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0)); Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment)); Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
@ -683,7 +684,8 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty), EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1), llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
llvm::ConstantInt::get(Int8Ty, TCK)}; llvm::ConstantInt::get(Int8Ty, TCK)};
EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData, Ptr); EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
PtrAsInt ? PtrAsInt : Ptr);
} }
// If possible, check that the vptr indicates that there is a subobject of // If possible, check that the vptr indicates that there is a subobject of
@ -2599,6 +2601,9 @@ llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) { llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
llvm::Type *TargetTy = IntPtrTy; llvm::Type *TargetTy = IntPtrTy;
if (V->getType() == TargetTy)
return V;
// Floating-point types which fit into intptr_t are bitcast to integers // Floating-point types which fit into intptr_t are bitcast to integers
// and then passed directly (after zero-extension, if necessary). // and then passed directly (after zero-extension, if necessary).
if (V->getType()->isFloatingPointTy()) { if (V->getType()->isFloatingPointTy()) {

3
clang/test/CodeGen/catch-undef-behavior.c
View File

@ -59,8 +59,7 @@ int bar(int *a) {
// CHECK-COMMON-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3 // CHECK-COMMON-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3
// CHECK-COMMON-NEXT: icmp eq i64 %[[MISALIGN]], 0 // CHECK-COMMON-NEXT: icmp eq i64 %[[MISALIGN]], 0
// CHECK-UBSAN: %[[ARG:.*]] = ptrtoint // CHECK-UBSAN: call void @__ubsan_handle_type_mismatch_v1(i8* bitcast ({{.*}} @[[LINE_200]] to i8*), i64 %[[PTRINT]])
// CHECK-UBSAN-NEXT: call void @__ubsan_handle_type_mismatch_v1(i8* bitcast ({{.*}} @[[LINE_200]] to i8*), i64 %[[ARG]])
// CHECK-TRAP: call void @llvm.trap() [[NR_NUW]] // CHECK-TRAP: call void @llvm.trap() [[NR_NUW]]
// CHECK-TRAP-NEXT: unreachable // CHECK-TRAP-NEXT: unreachable